A girl while walking diametrically across a semicircular playground, takes 3 minutes less than if she had kept walking round the circular path from A to B. If she walks 60 metres a minute, what is diameter of the play ground?
A. 60 m
B. 48 m
C. 84 m
D. 315 m
E. None of these
Answer: Option D
Solution (By Examveda Team)
Let the radius be r, then difference in the distance, πr - 2r = r (π - 2) = r [(3.14) -2] = 60 × 3 2r = 315 m. [πr = semi perimeter, 2r = diameter]This Question Belongs to Arithmetic Ability >> Speed Time And Distance
Why no one solve it alternatively?